It is known that certain tertiary amines can be converted to secondary amines, and secondary amines to primary amines, by electrochemical oxidation of amines containing phosphonomethyl groups, as described in U.S. Pat. No. 3,907,652 to John H. Wagenknecht and Kurt Moedritzer. A copending application of applicant Arnold Hershman, Ser. No. 465,976, filed May 1, 1974, and granted as U.S. Pat. No. 3,969,398 concerns a process employing molecular oxygen-containing gas and activated carbon catalyst to remove an acetic acid group from N-(phosphonomethyl) iminodiacetic acid.